U.S. patent number 10,367,135 [Application Number 15/147,551] was granted by the patent office on 2019-07-30 for method of fabricating a base plate for piezo actuation.
This patent grant is currently assigned to INTRI-PLEX TECHNOLOGIES, INC.. The grantee listed for this patent is INTRI-PLEX TECHNOLOGIES, INC.. Invention is credited to Damon Douglas Brink, David Django Dexter, Ryan J. Schmidt.
United States Patent |
10,367,135 |
Dexter , et al. |
July 30, 2019 |
Method of fabricating a base plate for piezo actuation
Abstract
A method of fabricating a base plate for piezoelectric
actuation, comprises providing a plate having a major surface,
striking a first removable portion of the plate in a first
direction substantially normal to the major surface to shear the
first removable portion relative to the plate by a shear distance
that is less than the plate thickness. Striking the first removable
portion in a second direction substantially opposite the first
direction to reduce the shear distance by a reduction in shear that
is less than the plate thickness. Leaving it the first removable
portion in place rather than removing. Alternately, the removable
portion may be created by lancing one or more portions spanning at
least one opening through a base plate adjacent a first side of at
least one opening and adjacent a second side of the at least one
opening.
Inventors: |
Dexter; David Django (Goleta,
CA), Brink; Damon Douglas (Ventura, CA), Schmidt; Ryan
J. (Santa Barbara, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
INTRI-PLEX TECHNOLOGIES, INC. |
Santa Barbara |
CA |
US |
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Assignee: |
INTRI-PLEX TECHNOLOGIES, INC.
(Santa Barbara, CA)
|
Family
ID: |
47554822 |
Appl.
No.: |
15/147,551 |
Filed: |
May 5, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160248000 A1 |
Aug 25, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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13186440 |
Jul 19, 2011 |
9361917 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
41/22 (20130101); G11B 5/4873 (20130101); H01L
41/053 (20130101); B21D 28/10 (20130101); G11B
21/10 (20130101); Y10T 83/0448 (20150401) |
Current International
Class: |
B21D
28/10 (20060101); G11B 21/10 (20060101); H01L
41/22 (20130101); G11B 5/48 (20060101); H01L
41/053 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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55-077941 |
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Jun 1980 |
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JP |
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55-103235 |
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Aug 1980 |
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JP |
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Primary Examiner: Tolan; Edward T
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. application Ser. No.
13/186,440 filed Jul. 19, 2011 for METHOD TO FABRICATE A BASE PLATE
FOR PIEZO ACTUATION.
Claims
What is claimed is:
1. A method of fabricating a base plate for a head suspension
assembly that prevents interlocking of multiple base plates when
packaged together and adds structural integrity during shipping,
the method comprising: providing a plate; creating at least one
opening through the plate, the plate including a first spanning
portion that extends from a first side of the at least one opening
to a second side of the at least one opening; lancing the first
spanning portion adjacent the first side and adjacent the second
side, so that the first spanning portion becomes removable by a
reduced shear force where lanced; leaving the first spanning
portion in place; packaging base plates with the first spanning
portion in place for shipping to a destination; and removing the
first spanning portion from each base plate upon receipt at the
destination.
2. The method of claim 1, wherein lancing comprises striking a
first surface of the first spanning portion with a lancing punch
along a first cleavage boundary that is adjacent the first side and
along a second cleavage boundary that is adjacent the second
side.
3. The method of claim 2, wherein lancing comprises striking a
second surface of the first spanning portion with a lancing punch
along the first cleavage boundary and along the second cleavage
boundary, the second surface of the first spanning portion being
opposite the first surface of the first spanning portion.
4. The method of claim 1, wherein the plate further comprises a
second spanning portion that extends from the first side to the
second side, and further comprising: lancing the second spanning
portion adjacent the first side and adjacent the second side, so
that the second spanning portion becomes removable by a reduced
shear force where lanced; and leaving the second spanning portion
in place rather than removing the second spanning portion.
5. The method of claim 1, wherein the first spanning portion
comprises at least a portion of a first edge of the plate such that
the at least one opening is not completely enclosed by the plate
without the first spanning portion.
6. The method of claim 1, further comprising: creating a second
opening separate from the at least one opening.
7. The method of claim 6, wherein the first spanning portion is
disposed between the at least one opening and the second
opening.
8. The method of claim 4, wherein the first spanning portion
comprises at least a portion of a first edge of the plate such that
the at least one opening is not completely enclosed by the plate
without the first spanning portion and the second spanning portion
comprises at least a portion of a second edge of the plate such
that a second opening through the plate is not completely enclosed
by the plate without the second spanning portion.
9. The method of claim 4, wherein the first spanning portion
comprises at least a portion of a first edge of the plate such that
the at least one opening is not completely enclosed by the plate
without the first spanning portion and the second spanning portion
comprises at least a portion of a second edge of the plate such
that the at least one opening through the plate is not completely
enclosed by the plate without the second spanning portion.
10. The method of claim 1, further comprising: removing a portion
of the base plate to form a swage opening for connecting the
baseplate to an actuator arm via a swaging operation.
Description
1. FIELD OF THE INVENTION
Implementations consistent with the principles of the invention
generally relate to the field of disk drive technology, more
specifically to methods of manufacturing piezo-capable base plate
assemblies.
2. DESCRIPTION OF RELATED ART
In conventional hard disk drives, data are stored on magnetizable
surfaces of a plurality of rotating disks that are mounted in a
coaxial stack on a housing of the drive. As shown and described in
U.S. Pat. No. 7,190,555, which is incorporated herein by reference
in its entirety, transducer heads that write data to and read data
from the disk surfaces may be supported by an actuator that is
mounted on the same housing and can be actuated to position the
transducer heads in alignment with concentric data tracks defined
on the disks. Each transducer head may be attached to one end of a
head suspension that is connected to an actuator arm that extends
from the actuator body. Each suspension may include a flexible base
plate. The suspension may act as a spring that forces the head
against the disk surface with an accurate load force or "gram
load." An air bearing caused by the rotating disks may lift the
heads slightly off of the disks so that the heads fly at a specific
height across the disk surfaces. The air bearing force may be
counteracted by the suspension gram load.
The head suspension may be attached to an actuator arm using a
conventional swage mount that forms a part of the head suspension.
The combined swage mount, base plate, and actuator arm make up the
head suspension, and the suspension has the hub of the swage mount
extending beyond the base plate and concentric with the clearance
hole.
FIG. 1 illustrates a disc drive assembly 100 including an actuator
arm 110, a base plate 120 and a swage mount 130. A fully assembled
disk drive may have an actuator arm assembly and a stack of
spaced-apart disks rotatable about a separate axis. The arm
assembly may include a plurality of actuator arms 110, which extend
into the spaces between the disks. One such actuator arm 110 is
shown in FIG. 1. Attached to the actuator arm near the tip 140 may
be a base plate 120. The actuator arm 110 when assembled in a stack
with a number of identical actuator arms may rotate about the
actuator arm axis 150.
The base plate 120 may include a base section 160 having a base
plate boss hole 170. The base plate 120 may include a resilient
section 180 located between the base section 160 and 10 a
protrusion section 190 of the base plate 120. The resilient section
180 may be formed to create an angular offset between the base
section 160 and protrusion section 190. The degree of bending of
the suspension may determine the downward preload force of a slider
toward a disk surface. The geometry of the base plate in resilient
section 180 and/or the size of an aperture 200 in the resilient
section 180 may establish the resilience of the base plate 120.
Piezo-driven actuation may be used to deform/deflect the base plate
to induce lateral motion of the protrusion section 190 of base
plate 120. As shown in FIG. 2, a pair of piezoelectric
microactuators 210 may be attached to opposite sides of aperture
200 in the resilient section 180 of base plate 120. Differential
electrical charges may be applied to each of piezoelectric
microactuators 210 to pivot protrusion section 190 of base plate
120 relative to base section 160 of base plate 120.
Various designs of piezo-capable base plates have been attempted in
the art. Many designs are difficult to handle after fabrication due
to nesting and interlocking of plates. For example, in the
exemplary piezo-capable base plate of FIG. 2, the aperture 200 may
permit interpenetration of multiple base plates after fabrication
and before installation of piezoelectric microactuators 210.
Handling of piezo-capable base plates may be difficult and may
cause problems with bonding piezoelectric elements. Many of the
designs in the art lack out-of-plane and lateral stiffness, which
can undesirably lower the resonant frequency of various suspension
modes. Current manufacturing attempts have failed to provide a
sufficiently compliant baseplate flange in the longitudinal piezo
actuation direction.
Thus, there is a need in the art for a cost effective means of
manufacturing base plates, while addressing the above issues or
other limitations in the art.
There is a need in the art for base plates that prevent nesting and
interlocking of multiple parts during fabrication and transfer from
initial fabrication to a later point in the assembly process, such
as the bonding of piezoelectric elements to the base plate or
ultimate incorporation into a disk drive assembly.
SUMMARY OF THE INVENTION
Various methods relating to manufacturing piezo-capable base plate
assemblies are disclosed and claimed.
In certain embodiments, a method of fabricating a base plate for a
head suspension assembly comprises providing a plate; creating at
least one opening through the plate, the plate including a first
spanning portion that extends from a first side of the at least one
opening to a second side of the at least one opening; lancing the
first spanning portion adjacent the first side and adjacent the
second side, so that the first spanning portion becomes removable
by a reduced shear force where lanced; and leaving the first
spanning portion in place rather than removing the 1 o first
spanning portion.
In certain embodiments, a method of fabricating a base plate for
piezoelectric actuation, comprises providing a plate defining a
plate thickness and having a major surface; striking a first
removable portion of the plate in a first direction that is
substantially normal to the major surface with a cutting punch to
shear the first removable portion relative to the plate by a shear
distance that is less than the plate thickness; striking the first
removable portion with a push back punch in a second direction
substantially opposite the first direction to reduce the shear
distance by a reduction in shear that is less than the plate
thickness; and leaving the first removable portion in place rather
than removing the first removable portion. In certain embodiments,
the reduction in shear is substantially equal to the shear
distance.
Other aspects and advantages of the present invention may be seen
upon review of the figures, the detailed description, and the
claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The exact nature of this invention, as well as the objects and
advantages thereof, will become readily apparent from consideration
of the following specification in conjunction with the accompanying
drawings in which like reference numerals designate like parts
throughout the figures thereof and wherein:
FIG. 1 is an exploded view of a disk drive magnetic head suspension
assembly;
FIG. 2 is a top view of a base plate including two piezoelectric
elements;
FIG. 3 is a top view of a base plate with a first spanning portion
according to certain embodiments of the invention;
FIG. 4 is a top view of a base plate with a first spanning portion
and a second spanning portion according to certain embodiments of
the invention;
FIG. 5 is a top view of a base plate with a lateral spanning
portion according to certain embodiments of the invention;
FIG. 6 is a top view of a base plate with an x-shaped spanning
portion according to certain embodiments of the invention;
FIG. 7 is a top view of a base plate with a spanning portion
according to certain 15 embodiments of the invention;
FIG. 8 is a side view of a section of a lanced base plate and a
lancing punch according to certain embodiments of the
invention;
FIG. 9 is a side view of a section of a base plate that has been
lanced on a first surface according to certain embodiments of the
invention;
FIG. 10 is a side view of a section of a base plate that has been
lanced on a first surface and a second surface according to certain
embodiments of the invention;
FIG. 11 is a top view of a base plate with a removable portion
according to certain embodiments of the invention;
FIG. 12 is a top view of a base plate with a removable portion
according to certain embodiments of the invention;
FIG. 13 is a side view of a section of a base plate and a cutting
punch according to certain embodiments of the invention; and
FIG. 14 is a side view of a section of a base plate and a push back
punch according to certain embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Certain embodiments of the invention relate to methods of
manufacturing piezo-capable base plate assemblies.
Base plates for use with piezoelectric microactuators may have
large openings where parts grouped together may undesirably
interlock. Additionally, it is desirable to produce base plates
that are sufficiently compliant to be deformed/deflected by
piezoelectric microactuators. However, the more compliant the base
plate is, the more likely it is to be damaged during handling. In
accordance with certain embodiments of the invention, a variety of
temporary structures may be used to prevent interlocking and to add
structural rigidity until removal at an appropriate stage of the
assembly process. For the purposes of this invention, lancing means
modifying a surface to create a cleavage line along which a
removable portion may be removed from a final part by a reduced
shear force. Methods for modifying the surface include but are not
limited to stamping, machining, etching, skiving, and other methods
known to those of skill in the art for creating a cleavage line
along which a removable portion may be removed from a final part by
a reduced shear force.
FIG. 3 shows a base plate 300 in accordance with certain
embodiments of the invention. Base plate 300 may be fabricated by
providing a plate 310 and creating at least one opening 320 through
plate 310. A first spanning portion 330 may extend from a first
side of the at least one opening 320 to a second side of the at
least one opening 320. The first spanning portion may be lanced
along a first cleavage boundary 340 adjacent the first side and
along a second cleavage boundary 350 adjacent the second side of
the at least one opening 320 so that the first spanning portion 330
becomes removable by a reduced shear force where lanced. The first
spanning portion 330 may be left in place rather than removed from
plate 310 to prevent interlocking of multiple base plates 300 and
to add structural rigidity until removal of first spanning portion
330 at an appropriate stage of the assembly process.
FIG. 4 shows a base plate 400 in accordance with certain
embodiments of the invention. Base plate 400 may be fabricated by
providing a plate 410 and creating a first opening 420 and a second
opening 430 through plate 410. A first spanning portion 440 may
extend from a first side of the first opening 420 to a second side
of the first opening 420. The first spanning portion may be lanced
along a first cleavage boundary 450 adjacent the first side and
along a second cleavage boundary 460 adjacent the second side of
the first opening 420 so that the first spanning portion 440
becomes removable by a reduced shear force where lanced.
A second spanning portion 470 may extend from a third side of the
second opening 430 to a fourth side of the second opening 430. The
second spanning portion may be lanced along a third cleavage
boundary 480 adjacent the third side and along a fourth cleavage
boundary 490 adjacent the fourth side, so that the second spanning
portion 470 becomes removable by a reduced shear force where
lanced. The first spanning portion 440 and/or the second spanning
portion 470 may be left in place rather than removed from plate 410
to prevent interlocking of multiple base plates 400 and to add
structural rigidity until removal of first spanning portion 440 and
second spanning portion 470 at an appropriate stage of the assembly
process. As shown in FIG. 4, first spanning portion 440 may
comprise at least a portion of a first edge of plate 410 such that
first opening 420 is not completely enclosed by the plate without
first spanning portion 440. Second spanning portion 470 may
comprise at least a portion of a second edge of plate 410 such that
second opening 430 is not completely enclosed by plate 410 without
second spanning portion 470.
FIG. 5 shows a base plate 500 in accordance with certain
embodiments of the invention. As shown, a first spanning portion
520 may extend laterally from a first side to a second side of an
opening 530 formed in plate 510. The first spanning portion 520 may
be lanced along cleavage boundaries 540 so that the first spanning
portion 520 becomes removable by a reduced shear force where
lanced. The first spanning portion 520 may be left in place rather
than removed from plate 510 to prevent interlocking of multiple
base plates 500 and to add structural rigidity until removal of
first spanning portion 520 at an appropriate stage of the assembly
process.
FIG. 6 shows a base plate 600 in accordance with certain
embodiments of the invention. Base plate 600 may be fabricated with
an x-shaped first spanning portion 610, which may be lanced along
cleavage boundaries 620 so that the first spanning portion 610
becomes removable by a reduced shear force where lanced. The first
spanning portion 610 may be left in place rather than removed from
plate 630 to prevent interlocking of multiple base plates 600 and
to add structural rigidity until removal of first spanning portion
610 at an appropriate stage of the assembly process.
FIG. 7 shows a base plate 700 in accordance with certain
embodiments of the invention. Base plate 700 may be fabricated by
providing a plate 710 and creating at least one opening 720 through
plate 710. A first spanning portion 730 may extend from a first
side of the at least one opening 720 to a second side of the at
least one opening 720. The first spanning portion may be lanced
along a first cleavage boundary 740 adjacent the first side and
along a second cleavage boundary 750 adjacent the second side so
that the first spanning portion 730 becomes removable by a reduced
shear force where lanced. The first spanning portion 730 may be
left in place rather than removed from plate 710 to prevent
interlocking of multiple base plates 700 and to add structural
rigidity until removal of first spanning portion 730 at an
appropriate stage of the assembly process. As shown in FIG. 7,
first spanning portion 730 may comprise at least a portion of a
first edge of the plate 710 such that at least one opening 720 is
not completely enclosed by the plate without first spanning portion
730.
FIG. 8 shows a method of lancing a surface according to certain
embodiments of the invention. Base plate 800 may be struck by
lancing punch 810 along a cleavage boundary 820 that separates a
first spanning portion 830 and plate 840 such that the first
spanning portion 830 becomes removable by a reduced shear force
where lanced. The first spanning portion 830 may be left in place
rather than removed from plate 840 to prevent interlocking of
multiple base plates 800 and to add structural rigidity until
removal of first spanning portion 830 at an appropriate stage of
the assembly process.
In certain embodiments, base plate 900 may be lanced by striking a
first surface of a first spanning portion 910 with a lancing punch
along a first cleavage boundary 920 of base plate 900, as shown in
FIG. 9. In certain embodiments, as shown in FIG. 10, base plate
1000 may be lanced by striking a first surface of a first spanning
portion 1010 with a lancing punch along a first cleavage boundary
1020 of base plate 1000 and striking a second surface of the first
spanning portion 1020 with a lancing punch along the first cleavage
boundary, the second surface of the first spanning portion being
substantially opposite the first surface of the first spanning
portion. One of skill in the art will understand that either of the
foregoing methods of lancing may be applied to any of the
embodiments illustrated in FIGS. 3-7.
FIGS. 11-14 shows a method of fabricating a base plate for
piezoelectric actuation according to certain embodiments of the
invention. The base plate 1100 may be fabricated by providing a
plate 1110, the plate 1110 defining a plate thickness 1320 and
having a major surface 1330. A first removable portion 1120 may be
struck in a first direction that is substantially normal to the
major surface 1330 with a cutting punch 1310 to shear the first
removable portion relative to the plate by a shear distance 1340.
The shear distance may be less than the plate thickness 1320.
The first removable portion 1120 may be struck with a push back
punch 1410 (shown in FIG. 14) in a second direction substantially
opposite the first direction to reduce the shear distance 1340 by a
reduction in shear that is less than the plate thickness 1320, such
that the first removable portion 1120 becomes removable by a
reduced shear force. The first removable portion 1120 may be left
in place rather than removed from plate 1110 to prevent
interlocking of multiple base plates 1100 and to add structural
rigidity until removal of first removable portion 1120 at an
appropriate stage of the assembly process. The reduction in shear
may be substantially equal to the shear distance.
One of ordinary skill in the art will recognize that the shear
distance 1340 may alternately be equal to or greater than plate
thickness 1320, resulting in temporarily pressing first removable
portion 1120 entirely out of plate 1110 and creating a first
opening in plate 1110. In such embodiments, push back punch 1410
may push first removable portion 1120 in a second direction
substantially opposite the first direction to reduce the shear
distance 1340, thereby forcing first removable portion 1120 back
into the first opening in plate 1110 to prevent interlocking of
multiple base plates 1100 and to add structural rigidity until
removal of first removable portion 1120 at an appropriate stage of
the assembly process. In such embodiments, the reduction in shear
may be substantially equal to the shear distance, such that major
surface 1330 of the first removable portion 1120 lies substantially
in a plane with a corresponding major surface of plate 1110.
FIG. 12 shows a base plate design with an alternative configuration
for the first removable portion according to certain embodiments of
the invention. The fabrication of base plate 1200 may include the
steps of fabricating base plate 1100 and may additionally include
creating at least one opening 1230 through plate 1210, the at least
one opening 1230 adjacent to the first removable portion 1220. The
fabrication of base plate 1200 may further include creating a
second opening 1240 separate from at least one opening 1230. The
first removable portion 1220 may be disposed between the at least
one opening 1230 and the second opening 1240. The first removable
portion 1220 may comprise at least a portion of a first edge of the
plate such that the at least one opening is not completely enclosed
by plate 1210 without first removable portion 1220.
One of ordinary skill in the art will recognize that a variety of
combinations of openings, spanning portions, and cleavage
boundaries may be utilized without deviating from the scope of the
invention and that the foregoing embodiments are exemplary and
non-limiting.
One of ordinary skill in the art will recognize that any portion of
the periphery of any 15 spanning portion described herein or
encompassed in equivalent embodiments of the invention may be
lanced so that the spanning portion becomes removable by a reduced
shear force where lanced. For example and without limitation,
rather than creating the at least one opening 720 in the embodiment
of FIG. 7, first cleavage boundary 740 may be connected to second
cleavage boundary 750 by lancing along the connecting periphery of
the area shown as 720 to form a composite cleavage boundary around
a first removable portion (720+730). The first removable portion
(720+730) may be left in place rather than removed from plate 710
to prevent interlocking of multiple base plates 700 and to add
structural rigidity until removal of first removable portion
(720+730) at an appropriate stage of the assembly process.
One of ordinary skill in the art further will recognize that in the
embodiments of FIGS. 11-14, and similar embodiments within the
scope of the invention, lancing may be used to create cleavage
line(s) along which a removable portion may be removed from a final
part by a reduced shear force, in lieu of the use of a cutting
punch and a push back punch as described with respect to the
embodiments of FIGS. 11-14.
One of ordinary skill in the art further will recognize that
removable spanning portions as described herein may be created by
any method for making such spanning portions removable by a reduced
shear force without limitation to lancing without departing from
the scope of the present invention without departing from the scope
of the present invention.
One of ordinary skill in the art further will recognize that a
portion of the base plate may be removed in any of the foregoing
embodiments to form a swage opening 170 for connecting the base
plate to an actuator arm via a swaging operation.
While the invention has been described with reference to the
specific embodiments thereof, it should be understood by those
skilled in the art that various changes may be made and equivalents
may be substituted without departing from the true spirit and scope
of the invention as defined by the appended claims. In addition,
many modifications may be made to adapt a particular situation,
material, composition of matter, method, operation or operations,
to the objective, spirit, and scope of the invention. All such
modifications are intended to be within the scope of the claims
appended hereto. In particular, while the methods disclosed herein
have been described with reference to particular operations
performed in a particular order, it will be understood that these
operations may be combined, sub-divided, or re-ordered to form an
equivalent method without departing from the teachings of the
invention. Accordingly, unless specifically indicated herein, the
order and grouping of the operations is not a limitation of the
invention.
* * * * *